Just started the other day --

Right around 1300-1500 rpm on the tach, the truck makes this (usually) slight grinding sound, not unlike the sound of a garbage disposal grinding something it shouldn't. A bit like metal on metal. I can't locate it, but -

1. It only happens right around those rpm's, no matter the speed.
2. Never in reverse, never during braking, never when coasting - ONLY when the accelerator is depressed.
3. While in the cab, it *sounds* like it is occurring under the passenger side of the hood, but it could be anywhere.

This led me to believe that it was just low transmission fluid, but after adding a little (it was a bit low), the sound persists.

I can't afford to have a huge transmission fix, but I'm getting nervous.

Any ideas as to what it might be?

Just started the other day --

Right around 1300-1500 rpm on the tach, the truck makes this (usually) slight grinding sound, not unlike the sound of a garbage disposal grinding something it shouldn't. A bit like metal on metal. I can't locate it, but -

1. It only happens right around those rpm's, no matter the speed.
2. Never in reverse, never during braking, never when coasting - ONLY when the accelerator is depressed.
3. While in the cab, it *sounds* like it is occurring under the passenger side of the hood, but it could be anywhere.

This led me to believe that it was just low transmission fluid, but after adding a little (it was a bit low), the sound persists.

I can't afford to have a huge transmission fix, but I'm getting nervous.

Any ideas as to what it might be?

The last, well, only time I had a sound like that it turned out to be the muffler. Had a rusty flap on top that would start vibrating under acceleration. Drove me nuts, finally took it to Cheseldyn. I was pretty relieved.

Sounds like the flux capacitor

Sounds like the flux capacitor

Alternator, belt idler bearing? Air conditioner compressor? Is it front wheel drive? CV joint?

Sounds like the flux capacitor

Couldn't be, because if it was, he would know what it was in the future and have traveled back in time to fix it before it made a noise.

Does it happen at that RPM regardless of speed? If so, you can probably rule out wheels, differential, driveshaft, brakes, etc...... and start looking for an engine, maybe tranny issue.

Alternator, belt idler bearing? Air conditioner compressor? Is it front wheel drive? CV joint?

All of those were suspect on my truck. I even replaced one idler pulley because I had conviced myself that must be the problem.

Sounds like the flux capacitor

1.21 Gigawatts!!! :jameo:

I'd make sure you muffler bearings are greased, your velocity stacks are topped off, your blinker fluid is clean, and your halogen levels check out. :shocking:

:)

Seriously, I'd check around the exaust for loose heat shield and otther loose pieces that may be vibrating / oscillating. Also check the balancer at the front of the engine... I had one that oscilatted too much and chewed off a crank sensor. :yay:

Start by driving it for a few minutes without the serpentine belt on. Rule out a lot of stuff.

Pretty much rule out AC. Does it exactly the same on or off.

Ditto CV joints. Nothing to do with turning. Not power steering either. Turn, don't turn - still the same sound.

Pattern seems to be the sound occurs around the same rpm no matter what speed it goes. At very low speeds - like in a parking lot - I don't hear it at all.
At higher speeds, again when the rpm isn't in range - I still don't hear it. Most of the time, it's when I get near that range - somewhere between 1300-1500 - it starts, and it is usually only a few seconds.

Sometimes it's loud, but most of the time it's somewhat faint.

My gut still says transmission, but I'd be glad to learn it's something a lot easier to fix.

The last, well, only time I had a sound like that it turned out to be the muffler. Had a rusty flap on top that would start vibrating under acceleration. Drove me nuts, finally took it to Cheseldyn. I was pretty relieved.


I'd be relieved too. Maybe I'll check that next. It sure sounds like METAL making the noise, but it sounds kind of "cyclical" - like something making the same sound every fraction of a second.

I'd be relieved too. Maybe I'll check that next. It sure sounds like METAL making the noise, but it sounds kind of "cyclical" - like something making the same sound every fraction of a second.

I had a loose exhaust hanger on a Ranger that drove me nuts.

I would check what others have said about exhaust and heat shields... have a friend drive and hang out the window to see if you can hear it, or stand in a parking lot and have them make a pass by you a few times to see if you can hear it on the outside; that is what led me to eventually find the hanger being loose.

Just started the other day --

Right around 1300-1500 rpm on the tach, the truck makes this (usually) slight grinding sound, not unlike the sound of a garbage disposal grinding something it shouldn't. A bit like metal on metal. I can't locate it, but -

1. It only happens right around those rpm's, no matter the speed.
2. Never in reverse, never during braking, never when coasting - ONLY when the accelerator is depressed.
3. While in the cab, it *sounds* like it is occurring under the passenger side of the hood, but it could be anywhere.

This led me to believe that it was just low transmission fluid, but after adding a little (it was a bit low), the sound persists.

I can't afford to have a huge transmission fix, but I'm getting nervous.

Any ideas as to what it might be?

Do you feel a vibration while it is occuring???

Do you feel a vibration while it is occuring???

Not really, and the thing that gets me is, it ONLY happens when the car is accelerating. It doesn't happen for instance, when I am coasting or braking. This leads me to believe it can't be something like a rattling part, which wouldn't care if my foot was on the gas or not.

Just started the other day --

Right around 1300-1500 rpm on the tach, the truck makes this (usually) slight grinding sound, not unlike the sound of a garbage disposal grinding something it shouldn't. A bit like metal on metal. I can't locate it, but -

1. It only happens right around those rpm's, no matter the speed.
2. Never in reverse, never during braking, never when coasting - ONLY when the accelerator is depressed.
3. While in the cab, it *sounds* like it is occurring under the passenger side of the hood, but it could be anywhere.

This led me to believe that it was just low transmission fluid, but after adding a little (it was a bit low), the sound persists.

I can't afford to have a huge transmission fix, but I'm getting nervous.

Any ideas as to what it might be?

Misfire? Do you have power or does it bog down under acceration Put it on a meter, connects under the steering wheel, check the code or take it to a shop, for 60 bucks they will check out the code.

If only while accelerating:
Weak Engine or Trans Mount would be something to check.
Put E Brake on, Hold Brake Pedal, Put in Gear, take up to rpm's in question.
:buddies:

Pretty much rule out AC. Does it exactly the same on or off.



Even when the A/C is off, the belt is still turning the pulley. Pulley = bearing. Bad bearing = noise.

That's why I suggested driving with the belt off entirely. You can rule out all the rotating accessories in one shot.

Had it looked at.

Sound is actually coming from the above or in the catalytic converter. So basically, it's either the heat shield rattling as the car vibrates (no biggie) or it's something inside the cat rattling around. That would account for it only happening when I step on the gas.

For the time being, I am not going to worry about it, unless I see performance problems. I have no wish or desire to replace the catalytic converter unless I need to, but thank God it isn't the transmission.

If there's something inside the CAT rattling around, you should check the CAT often for signs of discoloration and overheating. Fracturing or meltdown of the catalyst material is not normal and can result in a car-b-que when it begins to restrict exhaust flow.

Just started the other day --

Right around 1300-1500 rpm on the tach, the truck makes this (usually) slight grinding sound, not unlike the sound of a garbage disposal grinding something it shouldn't. A bit like metal on metal. I can't locate it, but -

1. It only happens right around those rpm's, no matter the speed.
2. Never in reverse, never during braking, never when coasting - ONLY when the accelerator is depressed.
3. While in the cab, it *sounds* like it is occurring under the passenger side of the hood, but it could be anywhere.

This led me to believe that it was just low transmission fluid, but after adding a little (it was a bit low), the sound persists.

I can't afford to have a huge transmission fix, but I'm getting nervous.

Any ideas as to what it might be?

If you have a 4X4 or a 4X2, it is possible the noise you are hearing is one of the "diff's" or one of the wheel hubs. Try jacking the truck up completely off the floor/ground and spin the tires one at a time and listen for grinding sounds. You may simply need to re-pack; and at worst re-place wheel bearings.

Sometimes the front hubs or the bearings can wear before the rear one's; or the bearings simply need replacing or grease. Try re-packing your wheel bearings in all four wheels; or just the one you think is making the noise. You know how to check 'em; right? If the first method doesn't satisfy your curiosity; remove the wheels, then disconnect the brake mechanism and check for wear; then remove and check wheel bearings; clean them thoroughly and spin 'em.
If they don't spin smoothly and/or if you hear grinding; it's time to replace them.

MY problem is; I've seen and done it enough to know how to do it; but to try to describe the procedure; I feel like I'm leaving a whole lot out.

have you looked under the vehicle?
are any of your nighbors missing their feral cats?

Had it looked at.

Sound is actually coming from the above or in the catalytic converter. So basically, it's either the heat shield rattling as the car vibrates (no biggie) or it's something inside the cat rattling around. That would account for it only happening when I step on the gas.

For the time being, I am not going to worry about it, unless I see performance problems. I have no wish or desire to replace the catalytic converter unless I need to, but thank God it isn't the transmission.

More unsolicited "expertise".....
Many times, if the heat shield is loose enough to rattle, it can be pulled out and/or cut out if necessary. Do you have a cut-off tool/die grinder if ya need one? I had a similar issue. Turns out, it was that very thing; pulled out the broken heat shield and the rattle stopped.:yay: Didn't have to turn up the radio to drown out the noise after that.

More unsolicited "expertise".....
Many times, if the heat shield is loose enough to rattle, it can be pulled out and/or cut out if necessary. Do you have a cut-off tool/die grinder if ya need one? I had a similar issue. Turns out, it was that very thing; pulled out the broken heat shield and the rattle stopped.:yay: Didn't have to turn up the radio to drown out the noise after that.

Mmm. so the heat shield serves no purpose except to make noise when it comes loose?




:lol:



;

Mmm. so the heat shield serves no purpose except to make noise when it comes loose?




:lol:



;

Naw.... totally expendable. They could save tons of money on new cars by eliminating them.

Naw.... totally expendable. They could save tons of money on new cars by eliminating them.

Probably sell a few more too!